Reed contact shear

ABSTRACT

A reed contact is formed from sheet metal by means of a punching operation. The end of the contact is designed so that any burrs resulting from the punching extend away from the contact surface into a kerf-shaped recess.

United, States Paten Eckstein et al.

REED CONTACT SHEAR lnventors: Walter Eckstein, Asperg; Roland Klotz,

Marbach, both of Germany International Standard Electric Corporation, New York, N.(.

Filed: Sept. 10, 1969 Appl. No.: 856,768

- Foreign Application Priority Data Assignee:

Sept. 25, 1968 Germany ..P 17 89 029.8

U.S.Cl .tss/46s,s3/4se lnt.Cl Field ofSearch 3/382, 454, 4-56, 465

References Cited UNITED STATES PATENTS [151 3,656,389 [451 Apr. 18, 1972 1,072,377 9/1913 Alley ..83/465 3,232,158 2/1966 Breeding ..83/465 X 3,367,223 2/ 1968 Caraisco et al. ..83/465 X Primary Examiner-Frank T. Yost AttorneyC. Cornell Remsen, Jr., Walter J. Baum, Percy P. Lantzy, J. Warren Whitesel, Delbert P. Warner and James B. Raden [5 7] ABSTRACT A reed contact is formed from sheet metal by means of a punching operation-The end of the contact is designed so that any burrs resulting from the punching extend away from the contact surface into a kerf-shaped recess.

2 Claims, 5 Drawing Figures PATENTEDAP 1 a 1912 3, 656 389 Q CT IJ 6 Fig. 7a

7 7 I A a iig h 6 Fig.1!)

Fig.2

Fig.3 7 Fig-4 INVENTOR BY W r NAM.

' ATTORNEY REED CONTACT SHEAR The present invention relates to reed contacts which are sealed into protective envelopes.

As a rule, magnetically controllable reed contacts as sealed into a protective envelope, are composed of two contact portions. In order to achieve small contact transfer resistance, the overlapping ends of the reed contacts or contact blades, when closed, must lie in planes which are parallel to each other. Contact bouncing phenomena are likewise reduced when the contacts are parallel to each other, thus increasing the service life of the contacts. Efforts are therefore made to keep any burrs resulting from punching the contact blades (reeds) as small as possible and to keep them from projecting into the contact plane. Attempts'to achieve these ends have involved the use of precision devices and special embodiments of the punching or stamping tools. Attempts have been made to remove or clean-off any remaining burrs with the aid of drumtype burr-removing devices.

Manufacturing the contact reeds in this way has proven to be expensive and involves high costs owing to the requirement that precise cutting devices be used and that any.remaining burrs be removed by means of drum-type deburring. It is therefore an object of the present invention to simplify the manufacture of reed contacts. It is another objective of the invention to increase the service life of the cutting tool, and thus to save costs.

According to the invention the foregoing objects are accomplished in that the contact end (A) of a reed is formed with a tapered projection and the cutting edge is formed in the kerf-shaped recesses of the projection.

According to one embodiment of the invention there is provided a device for manufacturing the reed contact using a cutting plate and a guide. In this embodiment the reed contact is retained in position with the aid of nose portions and a cutting punch is used to separatethe projection from the reed contact.

The present invention offers the advantage that the height of the burr is no longer of significance and that, consequently, drum-type deburring of the reed contacts is rendered superfluous. Moreover, it is possible for the cut or punched reed contacts to be placed into magazines in the proper position as they come out of the device, thus requiring no kinds of sorting works. Furthermore, it is to be considered as an important advantage that the edge life of the cutting tool is considerably increased when designing the reed contacts in accordance with the present invention. Owing to the absence of the burr in the contact plane, bouncing of the contacts is reduced and the service life of the reed contacts is extended.

The invention will now be described with reference to FIGS. 1 to 4 of the accompanying drawings, in which:

FIG. 1 shows a reed contact in both the top and side view;

FIG. 2 shows the contact end of the reed contact on an enlarged scale;

FIG. 3 shows the cutting tool prior to the cutting process; and

FIG. 4 shows the cutting tool according to FIG. 3 after the cutting process has been performed.

In FIGS. 1a and lb there is shown a reed contact 1 consisting of the soldering lug 6, the seal-in portion 7, and of the contact end A. This contact end A, in FIG. 2, is shown on an enlarged scale. From this it will be seen that the contact end A is tapered to form a projection 2. The cutting edge 3 of the reed contact 1 is thus no longer in connection with the contact plane 4. On account of this, the burr 5 resulting from the cutting (punching) is no longer of any noteworthy importance. The burr 5 as existing behind the contact plane 4, may reach the amount of the tapered portion up to fractions thereof without having any disturbing effect.

In FIGS. 3 and 4 there is shown the operation of cutting the projection 2 off the reed contact 1, as well as the device therefor. On a cutting plate 8 there is positioned the reed contact l which is retained in position by a guide 9 and by nose onions 1]. The projection 2 extends into the free space eneath the cutting punch 10. Upon lowering of the cu ting punch 10, the latter will separate the projection 2 from the reed contact 1. By displacing the burr 5 which results therefrom, behind the contact plane 4, it is no longer necessary to take care of achieving the best possible cutting. In this way the service or edge life of the cutting tool can be increased.

We claim:

1. A device for manufacturing a reed contact comprising a cutting plate and a guide adapted to receive and hold an essentially flat reed having a narrow part, a cutting punch for cutting a reed, said cutting plate and said guide each including a nose portion for engaging and clamping a narrow part of a reed, said cutting punch upon being lowered separating a reed into a contact part and a discardable part along a line through the narrow part of the reed, and said cutting punch pushing any burrs into the narrow part of the reed out of the way of a contact face of the reed to reduce the risk of making contact between the burrs and similar reed contacts.

2. A device as claimed in claim 1 in which the narrow point is formed by a kerf-shaped recess on each side of the reed, and any burrs formed by action of the cutting punch are formed in one of the kerf-shaped recesses where no electrical contact will be made by the burrs with other reed contacts. 

1. A device for manufacturing a reed contact comprising a cutting plate and a guide adapted to receive and hold an essentially flat reed having a narrow part, a cutting punch for cutting a reed, said cutting plate and said guide each including a nose portion for engaging and clamping a narrow part of a reed, said cutting punch upon being lowered separating a reed into a contact part and a discardable part along a line through the narrow part of the reed, and said cutting punch pushing any burrs into the narrow part of the reed out of the way of a contact face of the reed to reduce the risk of making contact between the burrs and similar reed contacts.
 2. A device as claimed in claim 1 in which the narrow point is formed by a kerf-shaped recess on each side of the reed, and any burrs formed by action of the cutting punch are formed in one of the kerf-shaped recesses where no electrical contact will be made by the burrs with other reed contacts. 